1. Field of the Invention
The present invention relates to a method for determining an intake air leakage to prevent a diesel particulate filter (DPF) from being damaged because particulate matters (PM) are excessively generated to be excessively deposited in the DPF due to a leakage of an intake system in a diesel vehicle with a low pressure EGR (hereinafter, referred to as ‘LPEGR’) mounted thereon and failures of a turbo charger and an engine from being caused because a part of the damaged DPF is introduced into an LPEGR system.
2. Description of Related Art
According to environmental regulations reinforced in recent years, the reduction of pollutants discharged from a vehicle is the object of the most important research and development in automobile industries of nations all over the world. Reduction measures such as combustion improvement and post-processing of HC, CO, and exhaust fumes in automobile exhaust gas are relatively easy, however, it is difficult to develop nitrogen oxide reducing technology due to a bad influence exerted to consumption and fuel efficiency. An exhaust gas recirculation (EGR) which is an exhaust gas recirculation device used as one of the nitrogen oxide reducing technology has been already commercialized as one of inexpensive and effective methods for reducing nitrogen oxide. CO2 or H2O of exhaust gas is substituted and mixed with some of intake air, such that a heat capacity of a mixer is increased to suppress an increase in temperature of combustion gas in a cylinder and an excess air factor is decreased to suppress generation of thermal NOx, thereby reducing a total amount of generated NOx. Further, since some of the intake air is substituted with exhaust gas having low oxygen density, the amount of oxygen in a combustion chamber is reduced, and as a result, generation of NOx is suppressed. In particular, the LPEGR developed against reinforcement of NOx regulations has been actively considered to improve fuel efficiency in recent years due to a high NOx reduction effect, and in the prior art, although the PM are excessively deposited in the DPF due to the leakage of the intake air, such that the DPF is damaged, the damaged DPF is not introduced into an engine, and as a result, a failure of the engine does not occur, however, in the LPEGR, some fragments of the damaged DPF are injected into the engine to cause the failures of the turbo charger and the engine.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.